摘要 |
<p>Method of forming a high-quality polycrystalline semiconductor thin film having large grain sizes by laser annealing. First, a film formation step is carried out to grow a semiconductor layer on an insulating substrate under certain film formation conditions, thus forming a precursory film. This precursory film comprises clusters of microscopic crystal grains. Then, an irradiation step is carried out. That is, the precursory film is irradiated with a laser beam such as an excimer laser pulse. The crystal sizes are increased to change the precursory film into a polycrystalline semiconductor thin film. During the film formation step, a precursory film having a crystal grain size of more than 3 nm is formed at a temperature of 500 to 650 DEG C, for example, by LPCVD or APCVD. Under these conditions, the resulting polycrystalline precursory film is substantially free from hydrogen. During the irradiation step, a single pulse of excimer laser radiation is emitted. <IMAGE></p> |